Some long-time Mac developers have reservations about Apple's Mac App Store, the online market set to launch Thursday.

Their beefs range from the technical to the philosophical, their worries running from support nightmares to a narrowing of consumer choice.

"Mac users may see a narrowing of what software is offered," said Jon Gotow, president of Blacksburg, Va.-based St. Clair Software . "I understand the rationale for Apple's rules -- to be successful, the App Store had to be as easy and bulletproof as the iOS store -- but the restrictions are going to cut out system utilities, and a lot of other things that are popular."

St. Clair's products are in that system utilities category. Default Folder X adds additional features to a Mac's Open and Save dialogs, while App Tamer automatically pauses applications when they're not in use, reducing CPU use and, on laptops, extending battery life.

The restrictions Gotow mentioned are numerous. Apple's Mac App Store guidelines list 92 prohibitions, including bans on software requiring the user's admin password, on programs that are not "self-contained, single application installation bundles," and on products that use an internal update mechanism rather than the App's Store own service.

Those limitations, said Gotow, will force developers to make a tough choice: Forgo the App Store and the audience drawn to its simplicity, or continue to sell direct, a strategy that Apple's new e-mart may make tougher as time goes by.

"Developers will self-censor the apps they develop," Gotow said. "For someone who's established, it's different, but if I was starting now, I wouldn't do Default Folder. If you're a new developer just getting started, you won't be creating something that isn't allowed in the App Store."

Gotow also worries that prices for Mac software will plummet.

"What's going to happen to prices?" he asked, acknowledging that he doesn't know. "[But] traditional developers don't want to sell something for $2."

He sees a split among developers. One group will base its business on high volume. "Do what they let us do, and just plow this stuff up," he said. The other will resent the 30% cut that Apple takes off the top for inclusion in the App Store.

"Apple's not giving us any user information, which is critical, and not letting us charge for upgrades, which will tend to encourage throw-away software," Gotow said.

"There will be no price race to the bottom," Nigrin said in a blog post yesterday. "This race is over before it even began. iOS developers will by and large adopt the same price points and the same strategies for the Mac."

That high-volume, low-price tactic may work for iOS developers bringing their products to the Mac, but it presents a big problem for people like Gotow.

"I don't spit out 10 apps a year," he said. "I do a product, introduce it and improve it, and keep it up for years."

Another Mac system utilities maker also complained about Apple's restrictions, calling one limitation "a disaster."

Bjango , best known for iStat Menus, believes that the rules will create a support nightmare.

"Not allowing upgrade pricing is something we can probably deal with, but not allowing support for older versions is a disaster," said Marc Edwards, director and lead designer at the company. "It creates a system where the likely outcome is for users to hate us at every major milestone of an app's life, except the initial release," he said in a blog post .

The support problem stems from the fact, said Edwards, that "there doesn't seem like any sensible way to support two versions of the same app on the App Store."

Bjango's take on the Mac App Store? "We want our Mac apps on the App Store, but we also need to ensure we can treat our customers with the respect they deserve," said Edwards. "Right now, that's not possible."

Things might change, Gotow said, pointing to modifications Apple made to its iOS App Store over the last two years. "I can see them relaxing the admin password restriction for certain classes of apps," he said, citing an example. "I think [the Mac App Store] will have more restrictions now than in the future."

But for the moment, he and other Mac developers he's talked to are taking a 'wait and see' approach to the new outlet.

"Apple is trying something new, and I think users will be very happy with the App Store user experience," Gotow said. "But innovation is often on the fringe of what's economically rewarding. That's one of my issues with the App Store."

Apple will launch the Mac App Store tomorrow, Jan. 6, and at the same time shut down its Mac OS X download site.